ON SATURDAY night, March 14, the Washington Opera will give the first of four performances of a great opera long neglected: "L'Amore dei Tre Re" by Italo Montemezzi. A creation in the best tradtion of Puccini and the passionate verismo school, it was written in 1911 and 1912, the time when Puccini was writing "La Funciulla del West."

Despite the power of its libretto and the expressive beauty of its lyrical orchestral and vocal writing, "L'Amore" has for years been left unperformed by the Metropolitan and Chicago operas, where it was popular in the early part of the century. Still it was done in Cincinnati in the late 1940s under the composer's baton and in San Francisco as recently as 1965. The opera was also performed, though not very successfully, but the NBC Opera Theater on television.

If the Washington Opera can bring this production off, it will be a major step toward a revival of one of the significant operas of this century.

The libretto, full of passion and revenge, is based on a 1910 play by Sem Beneli, about a barbarian king, Archibaldo, who, in the 10th century invades Italy from the north. He settles in its beautiful northern lake regions among people who never accept their subjugation. In hope of peace, Archibaldo arranges a marriage between his son, Manfredo, and Fiora, the princess of the conquered people. But Fiora has been promised to Avito, the king of the invaded region, and he and Fiora continue to meet in secret, passionate trysts when Manfredo is away at the wars.

Archibaldo, though blind, has long suspected his daughter-in-law of carrying on, though he does no know her lover's identity. Finally he comes upon them unexpectedly when they are being careless, and hearing the disappearing footsteps of the lover he can not see, he accuses Fiora. She at last fed up with the old man's constant accusations, rears up at him -- "like a serpent," Benelli's directions read -- and admits the whole thing. Archibaldo, in a towering rage, seizes her and, striking her head violently against a stone bench, throttles her to death.

In the final act, Fiora is laid out on a bier in the chapel crypt, a poison smeared on her lips by Archibaldo who is certain that her lover will come for a final kiss. When Avito does just that, he is discoverd by Manfredo who is crushed not only be his wife's death but by the realization that, although she did not love him, she was capable of an unbounded passion for Avito. "My God!" Mandredo cries. "Why can I not hate?"

As Avito dies of the poison, Manfredo, too, kisses his dead wife. As he is dying, his father comes in, expecting to catch the culprit, only to find that, having murdered Fiora, he has also caused his son's death.

Benelli's drama works superbly for Montemezzi, who knew from the beginning that he was the man to clothe it was music. For that music he drew upon the models of Verdi, Puccini and Wagner. "Music without melody is inconceivable," he wrote late in his life. "My main aim is to create the musical atmosphere in which the characters of the drama must live and express themselves."

His orchestra is full of gorgeous color, richly garbed in sounds that Wagner bequeathed to his successors. The harmonic thought in "L'Amore" is not unlike that of "Otello" or "Tosca" but has its own luxuriant texture. The voices soar freely in long melodic lines that rise as exultantly as those of Mimi, Aida or Isolde.

Early in the opera, which has only a brief orchestral introduction, there is a magnificent scene for Archibaldo. One of the grand moments for any bass, it describes the beauties of Italy as they unfolded before the eyes of the invading king. Shortly after its conclusion, Montemezzi introduces one of the two great love duets in the opera. When this is interrrupted by the skulking Archibaldo, the composer skillfully shows us the subtle differences with which Fiora speaks to her lover and her hated father-in-law.

Parallels between "L'Armore" and Wagner's "tristan" are strongest in the second act. In both operas there are extended love duets, each of which is interrupted by an offstage voice, and each of which is suddenly broken off by the unexpected arrival of an old king. There are even parallels in the language of Tristan-Isolde and Avito-Fiora, as the latter sing of "lasting enchantment, endless," much as Wagner's lovers long for "endless night."

A remarkable visual likeness suggests itself when Avito sings to Fiora, "Look up -- we are in heaven. We float through the skies," That is precisely the effect created in the Metropolitan's production of Tristan," in which the pair of lovers is raised high up above the stage to heighten the illusion of having left this earth entirely.

Another close resemblance exists between the love duet in "L'Amore" and the great duet that closes Act One of Verdi's "Otello." In Boito's sublime libretto, which is matched by that of Montemezzi's opera. Otello asks Desdemona for "a kiss, another kiss, and again a kiss." Avito tells Fiora, "Here, Fiora, a lovely kiss, the last of an infinity of kisses, the first of an eternity!"

"L'Amore dei Tre Re" received its premiere at La Scala in Milan in April 1913. The following season Arturo Toscanini conducted it at the Metropolitan, where it became an immediate hit.

During the next two decades "L'Amore," or "The Love of Three Kings," was taken up, especially in this country, by a striking succession of the rarest artists: Fiora was sung by Lucrezia Bori, Claudia Muzio, Rosa Ponselle and Mary Garden, four of the finest singing actesses. Avito its tenor, was sung by Caruso, Gigli, Martinelli, Edward Johnson and Charles Kullman, all famous leading men. The tremendous dominating role of the old blind king, Archibaldo, was a favorite of Adamo Didur, whom Ponselle said was its greatest exponent, while Garden claimed that Virgilio Lazzari, Chicago's favorite in the part, was unequaled. The taxing high baritone role of Manfredo was often sung by Stracciari,Danise, Amato and Bonelli.

The conductor's assignment in "L'Amore" is especially heavy since Montemezzi has loaded the score with specific dynamic and tempo instructions. Most of the great Italian conductors of the first half of this century made a specialty of the opera: Tullio Serafin presdied over its world premiere, Toscanini brought it to this country where Giorgio Polacco and Robert Moranzoni kept its passionate pages at white heat. In South America where it was also a favorite, Ettore Panizza was equally persuasive. a

In 1925 Montemezzi's work was popular enough to be chosen to open the season outdoor theater 25 miles north of Chicago, opera was given in the summers on the highest international level. Three years later Gatti-Casazza, general manager of the Met, chose it for his 1928 opener, with Ponselle as Fiora.

The singularly seductive texture of Ponselle's voice must have made her devastating in the part. When she sang it at Covent Garden a year after appearing in it at the Met, Ernest Newman wrote about her singing the very first word in her part: "Ponselle made the word 'Rotorniamo' so full of meaning that any divorce court would have given her husband a decree nisi." The word simply means "Let's go back in," which Fiora suggests to Avito when she discovers that they have arisen sooner than they needed to.

But success as Fiora does not require a voice of pure Italian sensuousness. It was the Spanish Bori, with a silvered voice capable of breaking her listeners' hearts in "Manon," who was said to produce the most devastating effect with her great cry of "Ah! tortura!" in the second act.

Mary Garden, with her lifelong slightly Scottish tinge of speech, and a voice that was a magical mixture of American and French, was one of the incomparable Fioras. Of her singing in the part, late in her career, Edward Moore wrote in the Chicago Tribune, that she and Rene Maison put on "a love scene that would cause hesitation in the mid of any right-minded movie censor."

Garden also demonstrated a unique devotion to the role of Fiora. In the last act, the only act with a chorus, a chamber group sings around Fiora's bier. Mary Garden always insisted on lying on that bier throughout the act. "I was Fiora for two acts until Lazzari killed me," she would say, "and I don't need any chorus girl or extra to take my place when I am dead!"

Why has an opera as grand as Montemezzi's and with so illustrious a history of performances been so neglected? The answer is probably a combination of factors involving the availability of outstanding artists to perform it and the interest of opera impresarios. There were many seasons during Rudolf Bing's reign at the Met, as well as in the Carol Fox years in Chicago, when exciting casts for this opera could have been assembled.

Performed at the Met, Jussi Bjorling or Giuseppe DiStefano, Licia Albanese or Zinka Milanov, Robert Merrill or Leonard Warren, Cesare Siepi or Giorgio Tozzi, the opera might have proven wholly worthy of the great traditions of the score. At the same time in Chicago, when Fox was specializing in precisely this kind of Italian repertoire, both Tebaldi and Callas were singing, surrounded by eminent Italian artists. But Callas herself once said, "No one asked me to sing it."

The Washington Opera has engaged Carol Neblett to sing Fiora, James McCray as Avito, Charles Long as Manfredo, and, for the grand part of Archibaldo, Jerome Hines, who should be magnificent in voice and appearance. aHe is tall enough and strong enough to hoist Fiora up onto his shoulders at the end of Act Two and stagger the entire length and depth of the stage in one of the most remarkable finales in opera. John Mauceri, who has studied the orchestral score from which the composer conducted the opera at the Metropolitan in the 1940s, will conduct, with Frank Corsaro in charge of the staging. The opera will be given on March 14, 18, 20 and 22.

It comes at a time when the Metropolitan is planning a revival of Mascagni's "Il Piccolo Marat," which derives from the same era, but which is vastly inferior. The Washington production of "L'Amore" is already scheduled to go to New York's City Opera and to Miami next season.